There has been a continuing need for a non-invasive means for taking samples of fluids, slurries and the like at precise selected sites in the animal alimentary canal. Generally, such sampling has been achieved by the use of tubes, syringes, endoscopic instrumentation and the like which are generally seen as stressful to the animal and undesirably invasive. Further, such means typically require tracking by undesirable radiation emission means and are highly dependent upon the manipulative skills of the physician gathering the sample and thus prone to human error.
The mechanical devices, which are preferred when the sampling is desired to occur at a specific site, are awkward implements, typically comprising long invasive needles or flexible tube mechanisms which are inserted into the alimentary canal with mechanically operated sampling means at the inserted end. The flexible devices are typically "snaked" into the alimentary tract through the mouth, nose or anal opening and generally require anesthetizing procedures to be acceptable to the animal being treated. Sampling, at a specific site in the tract, requires significant skill and typically must be done using elaborate locating means such as miniaturized video, fluoroscopic, X-ray apparatus or the like.
The medical profession has long recognized the need for more reliable means for the sampling of fluids, slurries and the like at specific alimentary canal sites, particularly means that might be accurately and repeatedly accomplished without confining the patient to a medical facility and without requiring the intensity of medical professional attention now required by typically available mechanical means.
In recent years, "radio pill" technology has been described wherein a capsule, containing a transmitter, has been seen by the medical profession as a possible means to monitor various body environments. It has been suggested that such pills could be implanted, ingested or otherwise placed at desirable locations in the body and could be engineered to transmit critical data to a remote receiver located outside the body. The ideal radio pill is seen as one that is small enough to be easily ingested, biologically inert, disposable and inexpensive. The transmission signal would have to be sufficiently strong to be received by a remote receiver, preferably located apart from the patient's body so that the patient would have freedom of movement, or, by a receiver small enough to be carried by the patient.
As a result of such recent perceptions, researchers from Heidelberg University developed a capsule and system for monitoring pH of the gastrointestinal tract. This capsule and system, generally known as the Heidelberg pH capsule system, comprises a capsule containing a transmitter that is sensitive to pH changes experienced within the gastrointestinal tract. The patient wears a belt, which contains an antenna for collection of transmitted signals, which in turn feeds the signals to a receiver. The receiver stores and/or records the data, generally on a graph, thus providing the medical professional with a non-invasive means to monitor pH within the alimentary canal. Geographic location is not determined using the radio signals. Though the Heidelberg capsule system does allow some freedom of movement for the patient, it requires tethering of the patient to bulky machinery and has not enjoyed widespread commercial success, probably because of the limited use for the information gathered.
Another radio pill that has been recently developed is that generally known as the Konigsberg temperature telemetry pill. The Konigsberg pill is an ingestible capsule comprising a transmitter that is sensitive to temperature changes. As with the Heidelberg capsule, signals are transmitted to a collecting antenna and then to a receiver where the data is stored and/or recorded for use by the medical professional. Again, as with the Heidelberg capsule, geographic location of the capsule is not determined using the radio signals.
Each of the Heidelberg and Konigsberg capsules have utility in the short term monitoring of pH, but neither have the ability to collect a sample at a selected site.
An object of the present invention is to provide a capsule which is easily ingestible in an animal alimentary canal and can be remote triggered to collect a sample of fluid, slurry or the like at a specified site in the canal.
Another object of the invention is to provide a capsule that can transmit a signal to a remote receiver, sufficient to determine geographic location of the capsule within the alimentary canal.
A further object of the invention is to provide a process for the tracking of a capsule through the alimentary canal.
A still further object of the invention is to provide a process for tracking a capsule through the alimentary canal and gather a desired fluid sample at a specified site within the canal.
These and other objects of the invention will become apparent from the following description of the invention.